Cardiovascular disease [CVD], a diagnosis that indicates dysfunction of the heart and/or blood vessels resulting from atherosclerosis, places patients at risk for heart valve dysfunction, arrhythmias, heart attack and stroke.1 Hypertension, hyperglycemia, high cholesterol, tobacco use, physical inactivity, unhealthy diet and being overweight or obese are modifiable risk factors for CVD.2 Being overweight or obese increases the work demand of the heart. It also increases blood pressure, cholesterol, and triglycerides, and reduces cardio-protective high-density lipoproteins [HDL].1
Throughout this paper, we will focus on body mass index [BMI] to describe weight status. For children, age and gender are factored into BMI so that a BMI less than 5% indicates underweight, a BMI of 5-85% indicates a normal weight, a BMI from 85-95% indicates overweight, and a BMI greater than 95% is considered obese.
Consequences of Obesity in Childhood
The Healthy People 2020 guidelines published in 2010 identify obesity as a common contributor to the decline of cardiovascular health.3 A study in 2011 found that children with obesity were more likely to become obese adults than those who were not obese as children.4 This research upholds the Healthy People 2020 statement that consequences of adult obesity include: increased risk of developing chronic diseases, such as CVD, type 2 diabetes [T2D] and certain cancers.3 A systematic review concerning childhood obesity and adult CVD risk questioned "whether childhood obesity exerts an independent effect on adult cardiovascular health [. since] some studies suggest quite the opposite, with those who were thinnest as children and overweight as adults showing the highest adult metabolic risk." 5 Other studies have found that accelerated BMI gains in childhood, particularly at 7-11 years of age, put children at highest risk of CVD and T2D in adulthood.4
Therefore, tracking the growth of children becomes paramount for detection and prevention of prolonged accelerated gains in BMI during vulnerable early development periods. Identifying opportunities to promote appropriate physical activity and maintenance of a healthy diet in children and adolescents potentially limits development of modifiable risk factors associated with CVD in adults, namely: hypertension, hyperglycemia, high cholesterol, physical inactivity, unhealthy diet and being overweight or obese.1 The purpose of this literature review is to answer the question: "Are children ages 5-17 who are obese (BMI > 95%) compared with those of normal BMI (5-85%) at higher risk for developing cardiovascular disease as an adult?"
Whether issues arise specifically from obesity over time or from a sharp rise in BMI in early development, there is a consensus in the literature on two counts. The first is that obesity in adulthood yields an increased risk of chronic illness, including but not limited to the decline of cardiovascular health. The second is that obese children are more likely to become obese adults. Specifically, we wish to examine whether pediatric patients of normal weight, who participate in age-appropriate exercise regimens and engage in cardio-protective behaviors, prevent chronic illness.
Articles demonstrate the link between obesity and CVD and an indication for early intervention. A British cohort study found that children and adolescents who were obese at any point in their early life along with obesity in adulthood had increased odds of T2D, hypertension or coronary heart disease.6 However, it was also observed that those who were overweight in childhood or adolescence, but were not overweight in adulthood did not have an increased risk for T2D and hypertension.6 (p3-4) Since being overweight during childhood is believed to have a direct effect on cardiovascular issues during adulthood, the research features early life as an important target time to address prevention and treatment of obesity.6
Link between Childhood BMI and CVD
A quantitative cohort study conducted at a pediatric obesity care center found that 31.2% of the 774 patients in treatment between ages 1.7 and 17.9 years of age had already developed "cardiovascular disturbances" by the time they were admitted.7 Requisite criteria for participation in the study included a BMI z-score above one standard deviation from the mean. Retrospective and prospective data were collected. Hypertension was present in 17% of participants, systolic hypertension increased almost 5 fold for extremely obese children, and lipid anomalies were present in almost a third of overweight to obese subjects.7 The correlational coefficient between BMI z-scores and prevalence of cardiovascular complications was statistically significant. Therefore, the study concluded that with a decrease in weight, producing a decrease in BMI, the individual's potential for developing cardiovascular disease also decreases. 7
Concurrent with the findings of previous studies, obese adults are at increased risk for chronic diseases, such as CVD, T2D and certain cancers. Furthermore, results indicate that obese children are more likely to be obese in adulthood than children of normal weight. To further support this idea, a cohort including approximately 17,000 participants was followed over time to age 50 years.4 This study found that the greatest predictor of adult obesity was an elevated BMI in participants at age 16 and the most common noted cardiovascular risk factors for the participants at age 45 were obesity, hypertension, high triglycerides and elevated LDL cholesterol. 4
Utilizing longitudinal research design, the Bogalusa Heart Study, a community based, epidemiologic study of cardiovascular disease, provides further evidence of childhood obesity leading to adult cardiovascular health decline.8 Researchers found more than half of overweight or obese adolescents remained overweight or obese in adulthood and had elevated blood pressure, cholesterol, insulin, and glucose levels.8 Most notably, the presence of hypertension was increased 8.5-fold in the overweight or obese cohort of adults.8
Obesity and Metabolic Disease
Utilizing the data from the Bogalusa Heart Study cohort, additional researchers wished to study the longitudinal relationship between childhood BMI and adult levels of lipids, insulin, and blood pressures.9 Children ages 5 to 17 years old were eligible for this study with reexamination occurring between the ages of 19 and 35 years. This study found childhood obesity was not associated with increased adverse cardiovascular risk factors in adulthood, and risk factor levels among obese adults did not differ between those who had been normal weight or overweight as children.9 One problem with these findings was the final age of reexamination of participants. It is reasonable that lifetime risk of developing CVD has not yet been established by age 35. Therefore, it is not possible to accurately deny that childhood obesity might have developed into cardiovascular disease in these individuals as adults.
Goran, Ball, and Cruz conducted a secondary data analysis of the effects of body fat, abdominal fat, ethnicity, onset of puberty, and BMI on development of CVD and T2D.10 From their research, they determined that obesity-related conditions observed in early life is more likely an intrinsic process than a function of aging or deteriorating biological phenomenon.10 They discovered that a link between obesity and metabolic and cardiac diseases is present.
Cormobidities of Childhood Obesity
Many researchers have bypassed the umbrella statement that obesity leads to cardiovascular disease by describing instead the ways in which childhood obesity leads more specifically to additional risk factors for cardiovascular disease, such as dyslipidemia. For example, Freedman, et al9 did not necessarily link childhood obesity to adult cardiovascular disease, but describe a link between obesity and adult cardiovascular disease markers such as lipids, lipoproteins, blood pressure and insulin levels. Martinez Costa, et al11 explained the increase of body fat in childhood and adolescence has medium to long-term consequence. Consequences include: dyslipidemia, diabetes, metabolic syndrome, hypertension, fatty liver, biliary disease, orthopedic disorders, respiratory and psychological issues.11
Center for Disease Control (CDC) growth standards and the World Health Organization (WHO) criteria were used to calculate BMI for the children. Total cholesterol, high density lipoprotein, low density lipoprotein, total glucose, and uric acid were measured while the child or adolescent was fasting. The blood pressure and measurement of the right common carotid artery were also measured in each participant. According to Martinez Costa, et al, 11 48%, by CDC standards, and 43%, by WHO standards, of the children were considered obese. Overweight children showed higher blood pressures, insulin, and uric acid levels than children of normal weight. The greater the degree of obesity, the higher the likelihood that a child would be found to have additional comorbidities.11
The evidence exists to support the hypothesis that children who are obese are indeed at increased risk for developing cardiovascular disease during adulthood. According to the American Academy of Pediatrics12, "prevalence of pediatric obesity has increased significantly in the past few decades and is now recognized as a public health priority." There is ample evidence in the research to suggest a strong link exists between childhood obesity and the development of one or more additional risk factors for heart disease over time. Factors include increased lipid levels with resulting atherosclerotic plaques, hypertension, valve or vascular damage, ischemic changes of the heart muscle, and finally cardiac events.
Post mortem and adverse events statistics demonstrated that ill effects of obesity on the cardiovascular system may be noted as early as childhood, early adolescence, and young adulthood. Other research suggests that incidence of CVD or adverse cardiac events subsequent to or concurrent with obesity occur with greater frequency as an individual ages.9 In either case, however, there is a positive relationship between being obese and developing heart disease.
According to the American Academy of Pediatrics12, "It is never too early for the family to make changes that will help a child keep or obtain a healthy weight." Healthy eating habits and physical activity should be encouraged for all children to promote a healthy weight and aerobic exercise to strengthen the heart. These should be tailored to the child's developmental stage and family characteristics. In efforts to promote long-term cardiovascular health, advancing the mission of Healthy People 20203, which calls for education about and prevention of risk factors for cardiovascular disease, we propose that educational materials be created and distributed by health care providers who care for children and adolescents. During subsequent office visits, follow up conversations, which assess for understanding, compliance with, and results of diet and exercise interventions, should be evaluated and documented.
Current recommendations by the American Academy of Pediatrics,12 include but are not limited to, reducing screen time (when children are largely physically inactive), and increasing participation in activities such as team sports, playing at the park, walking or riding bikes, using the stairs or walking the dog. According to the CDC13, sources such as families, communities, schools, medical care provider and the media are largely influential in the success of such initiatives. In order for the patient to be successful, it is vital for the parent to model the behaviors expected of the child.
Therefore, parents or guardians should be assessed for willingness as well as the child. When ready, the American Academy of Pediatrics12 suggests the following small changes be made, having discussed healthy BMI promotion with a provider: change the foods brought into the home, buy fewer sugar-sweetened beverages and high calorie snacks, make choosing a healthy snack easily visible (water, raw vegetables and fruits pre-washed and ready-to-eat), reducing screen time, adjusting bedtime to allow for 9 or more hours of sleep per night and ensuring at least 60 minutes of activity per day.
For additional support and resources, parents of children with increased BMIs are encouraged to visit the American Academy of Pediatrics Institute for Healthy Childhood Weight14 at https://ihcw.aap.org/Pages/default.aspx or Children's Healthcare of Atlanta's Strong 4 Life Campaign15 at http://www.strong4life.com
Tina Campbell and Kayla Gee practice family medicine in Georgia. Patricia Hernandez works as a pediatric nurse.
1. American Heart Association. What is cardiovascular disease? http://www.heart.org/HEARTORG/Caregiver/Resources/WhatisCardiovascularDisease/What-is-Cardiovascular-Disease_UCM_301852_Article.jsp#. Accessed March 20, 2016.
2. World Heart Federation. Cardiovascular disease risk factors. http://www.world-heart-federation.org/press/fact-sheets/cardiovascular-disease-risk-factors. Accessed March 20, 2016.
3. U.S. Department of Health and Human Services, Office of Disease Prevention and Health Services. Heart Disease and Stroke. Healthy People 2020. https://www.healthypeople.gov/2020/topics-objectives/topic/heart-disease-and-stroke. Accessed March 20, 2016.
4. Li L, Pinot de Moira A, Power C. Predicting cardiovascular disease risk factors in midadulthood from childhood body mass index: utility of different cutoffs for childhood body mass index. Am J Clin Nutr. 2011;93(6):1204-1211. doi:10.3945/ajcn.110.001222
5. Lloyd L, Langley-Evans S, McMullen S. Childhood obesity and adult cardiovascular disease risk: a systematic review. Int J Obes. 2010;34(1):18-28. doi.org/10.1038/ijo.2009.61
6. Park MH, Sovio U, Viner RM, Hardy, RJ, Kinra S. Overweight in childhood, adolescence and adulthood and cardiovascular risk in later life: pooled analysis of three British birth cohorts. PLoS One. 2013;8(7):1-6. doi:10.1371/journal.pone.00706847. Maggio A, Martin X, Saunders Gasser C, et al. Medical and non-medical complications among children and adolescents with excessive body weight. BMC Pediatr. 2014;14(1):232.
8. Srinivasan SR, Bao W, Wattigney WA, Berenson GS. Adolescent overweight is associated with adult overweight and multiple related cardiovascular risk factors: the Bogalusa heart study. Metabolism. 1996;45(2):235-240. doi.org/10.1016/S0026-0495(96)90060-8
9. Freedman D, Khan L, Dietz W, Srinivasan S, Berenson G. Relationship of childhood obesity to coronary heart disease risk factors in adulthood: the Bogalusa heart study. Pediatrics. 2001;108(3):712-718.
10. Goran MI., Ball GDC, Cruz, ML. Obesity and risk of type 2 diabetes and cardiovascular disease in children and adolescents. J Clin Endocrinol Metab. 2003;88(4):1417-1427. doi.org/10.1210/jc.2002-021442
11. Martínez-Costa C, Núñez F, Montal A, Brines J. Relationship between childhood obesity cut-offs and metabolic and vascular comorbidities: comparative analysis of three growth standards. J Hum Nutr Diet. 2014;75-83. doi:10.1111/jhn.12140
12. American Academy of Pediatrics. AAP updates recommendations on obesity prevention: it's never too early to begin living a healthy lifestyle. https://www.aap.org/en-us/about-the-aap/aap-press-room/pages/AAP-Updates-Recommendations-on-Obesity-Prevention-It's-Never-Too-Early-to-Begin-Living-a-Healthy-Lifestyle.aspx. Accessed March 20, 2016.
13. Center for Disease Control. Childhood obesity facts. http://www.cdc.gov/obesity/data/childhood.html. Accessed March 20, 2016.
14. American Academy of Pediatrics. Institute for healthy childhood weight. https://ihcw.aap.org/Pages/default.aspx. Accessed March 20, 2016.
15. Children's Healthcare of Atlanta. Strong 4 life. http://www.strong4life.com/?utm_medium=cpc&utm_source=bing&utm_campaign=Strong4Life-EM&utm_term=strong-for-life&utm_content=Strong4Life. Accessed March 20, 2016.